In my mechanical import and export company, I often receive repair requests from customers. When I open the returned machines and look at the carbonized spark plugs and the worn piston rings due to sand and dust, I always feel extremely distressed. I often say that machinery has a soul, and if you deceive it, it will deceive your schedule. Today, I won't talk about sales. As an old mechanic, I will share with you my long-hidden maintenance secrets. I guarantee that if you follow what I s